The present disclosure relates to image forming apparatuses that include conveying portions in which toner to be discarded is conveyed.
In conventional arts, image forming apparatuses that form toner images on sheets include collecting devices that collect toner to be discarded. The collecting device includes a conveying portion and a collecting container. Toner, to be discarded, generated in units of the image forming apparatus is conveyed to the collecting container by the conveying portion. The conveying portion includes a screw member which is rotated, and conveys, in a predetermined conveying path, the toner to be discarded. A conveying capability of the conveying portion is limited. Therefore, if a great amount of toner to be discarded is conveyed by the conveying portion, load on the screw member becomes excessively heavy, and the screw member may be damaged. Therefore, a technique is known in which, when the screw member indicates an abnormal torque value, the apparatus is stopped as immediately as possible, and a warning is issued to a user.
However, stopping of the image forming apparatus is inconvenient for a user, and it is desired that an image forming operation is performed as continuously as possible. In order to address this, a technique is known in which, when load on the conveying portion becomes excessively heavy, restoration of an operation of the conveying portion is executed. Specifically, even in a case where toner to be discarded is accumulated in the conveying path, and load on the conveying portion is increased, if the conveying path is not full of the toner to be discarded, the conveying portion is continuously driven. Due to the forced driving of the conveying portion, the accumulated toner to be discarded is dispersed, thereby restoring a torque of the conveying portion.